What is meant by resistance of a galvanometer?
Table of Contents
- 1 What is meant by resistance of a galvanometer?
- 2 What effect does the resistance of the galvanometer have in the circuit?
- 3 How do you calculate galvanometer deflection?
- 4 Why does galvanometer show half value?
- 5 What is the purpose of using resistance in series with galvanometer does it affect the null point?
- 6 How many resistance are used in Wheatstone bridge?
- 7 How do you convert a galvanometer to a voltmeter?
- 8 What is the working principle of moving coil galvanometer?
What is meant by resistance of a galvanometer?
the galvanometer resistance equals that value of the variable resistance in the two methods. which gives the same second deflection. A new method which resembles the Kelvin method of. obtaining the resistance of a galvanometer is reported.
How much is the resistance of galvanometer?
The initial resistance of the galvanometer is equal to 50 ohms. The maximum value of the current that can be passed through a galvanometer is 0.002 A.
What effect does the resistance of the galvanometer have in the circuit?
The resistance of a galvanometer is 10Ω. It gives full-scale deflection when 1 mA current is passed.
How do you find the resistance of a galvanometer?
Derivation of G = RS ÷ (R – S):
- and are keys.
- G is the resistance of the galvanometer.
- E is EMF of the cell.
- I is current.
- H.R.B is high resistance box.
- L.R.B is low resistance box.
How do you calculate galvanometer deflection?
I = (C / nBA) × θ where C is the torsional constant of the spring; i.e. the restoring torque per unit twist. A pointer attached to the spring indicates the deflection θ on the scale.
How do you calculate the resistance of meter bridge?
This experiment is based on the principle of wheatstone bridge having the null deflection value. The formula for finding the unknown resistance is X = 100-l / l * R.
Why does galvanometer show half value?
The quantity of current required to produce a deflection of one division in the galvanometer is called figure of merit of a galvanometer . Its unit is ampere per division . Why is this method called half deflection method? It is so because the deflection is made half by using a shunt resistance S.
What is the purpose of using resistance in series with galvanometer?
We can construct ammeters using a galvanometer by attaching a high resistance in parallel to the galvanometer. The parallel combination ensures that all current flows through the galvanometer while the high resistance doesn’t allow current to pass through itself.
What is the purpose of using resistance in series with galvanometer does it affect the null point?
* It is a null method. Hence the internal resistance of the cell and the resistance of the galvanometer do not affect the null point… As the method does not involve any measurement of current and potential difference, so the resistances og ammeters and voltmeters do not affect the measurements.
Does galvanometer have variable resistance?
It is shown that the correct value is the geometric mean of the results of the two methods, if the initial deflections are the same in the two cases; also, the galvanometer resistance equals that value of the variable resistance in the two methods which gives the same second deflection.
How many resistance are used in Wheatstone bridge?
four resistances
This bridge consists of four resistances P, Q, R and S connected along four sides of a square (say ABCD) shaped circuit.
Why does a galvanometer have such a small resistance?
It has a small resistance because the classical “galvanometer” involves a small coil, carrying the test current, and suspended in a strong DC magnetic field, the orientations of the field and the coil being such that a current in the coil would “torque” the coil, thereby moving the indicator needle.
How do you convert a galvanometer to a voltmeter?
A galvanometer is converted into a voltmeter by connecting it in series with high resistance. A suitable high resistance is chosen depending on the range of the voltmeter. I G = Total current passing through the galvanometer which corresponds to a full-scale deflection.
What is the maximum deflection current in the galvanometer?
The maximum deflection current in the galvanometer is 100μA. Find the current in the circuit, so that the ammeter shows maximum deflection. (IIT-JEE|2005) I= (1+R G / R S ).
What is the working principle of moving coil galvanometer?
The angle through which the coil is deflected due to the effect of the magnetic torque is proportional to the magnitude of current in the coil. The moving coil galvanometer is made up of a rectangular coil that has many turns and it is usually made of thinly insulated or fine copper wire that is wounded on a metallic frame.